1. Field of the Invention
The present invention relates to the structure of a door beam arranged in a main body of a door in a vehicle.
Priority is claimed on Japanese Patent Application No. 2005-374507, filed Dec. 27, 2005, the content of which is incorporated herein by reference.
2. Description of the Related Art
In a known door beam structure, an end of a door beam, made from a steel pipe, is cut diagonally so as to improve the yield and reduce the weight thereof (see Japanese Unexamined Patent Application, First Publication No. H9-226369).
In the above conventional structure, the closer to the head of the door beam, the smaller the rigidity of the beam. Therefore, a measure for suppressing such a decrease in the rigidity is required, and such a measure may cause complication of the process for manufacturing the door beam. In order to solve this problem, the door beam may be made by press-molding so as to improve flexibility for design. However, also in this case, it is necessary to sufficiently consider improvement of the yield and reduction of the weight.